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Encounter Identity Subjects

The Encounter Identity Subject identifies a patient encounter that exists in the real world. Some examples of patient encounters are outpatient check-ups (e.g. doctor's office visits), inpatient hospital stays, acute care, occupational therapy etc.

Encounter subjects have the following attributes:

Subject Label	"Encounter"
Subject type	Identity
Synchronization	Constant
Security	None
Subject Dependencies	Dependent on patient subject
Mapping Agent Coupon Value	-3

Different applications have different methods of identifying a patient encounter. Some applications may combine the values of multiple identifiers in order to create a unique Encounter identifier. The concept of an encounter can be different for different applications. Use of the same identifier values to represent different real world patient encounters by different applications is common. For example, two different applications may use the same visit number to represent two different encounters for the same patient. Therefore, all context subject items should use site-defined suffixes to define Encounter subjects. An Encounter Link-enabled application should be configurable to use the appropriate suffix (or suffixes) to get or set the Encounter context data.

Encounter subjects have the following standard context data items. An Encounter Linked application should set the value for at least one of the items listed in the following table:

Encounter Subject Identifier Item Name	Meaning	Data Type	Semantic Constraints on Values	Case Sensitivity
Encounter.Id.VisitNumber.Suffix	Visit Number, per PV1-19	ST	HL7 Table 0203 Identifier Type = VN	No
Encounter.Id.AlternateVisitId.Suffix	Alternate Visit Id, per PV1-50	ST	HL7 Table 0203 Identifier Type = VN	No
Encounter.Id.AccountNumber.Suffix	Account Number, per PID-18	ST	HL7 Table 0203 Identifier Type = AN	No

An application can optionally set values for the corroborating items listed in the following table:

Encounter Subject Corroborating Item Name	Meaning	Data Type	Semantic Constraints on Values	Case Sensitivity
Encounter.Co.VisitIndicator.Suffix	Visit indicator, per PV1-51	IS	HL7 Table 0326	No
Encounter.Co.AdmitDateTime.Suffix	Admission date/time, per PV1-44	TS	None	No
Encounter.Co.PatientClass.Suffix	Patient class, per PV1-2	IS	HL7 Table 0004	No
Encounter.Co.AdmissionType.Suffix	Admission type, per PV1-4	IS	HL7 Table 0007	No
Encounter.Co.AssignedPatientLocation.Suffix	Patient's current location, per PV1-3	PL	None	No
Encounter.Co.ServicingFacility.Suffix	Servicing facility, per PV1-39	PL	HL7 Table 115 This field is used in a multiple facility environment to indicate the facility with which this visit is associated.	No
Encounter.Co.PatientType.Suffix	Type of patient, per PV1-18	IS	HL7 Table 0018	No

Note: It is highly recommended to set the Visit Indicator item explicitly.

Examples of Encounter Subject Items are listed in the following table:

Example Item Names	Example Item Values
Encounter.Id.VisitNumber	12345A
Encounter.Co.AdmitDateTime	20090627
Encounter.Co.DischargeDateTime	20090628